A wave plate is known as an element for controlling polarization. For example, incident light having linearly polarized light can be changed to the light having linearly polarized light in any direction, by rotating the wave plate around the optical axis. Conventionally, a wave plate constituted by a medium having refractive index anisotropy has been generally used. When the refractive index anisotropy exists in the medium, a traveling speed of the light changes depending on the direction of the polarized light, therefore phase of the emitted light changes relative to phase of the incident light. An amount of change in phase at the time is in inverse proportional to a wavelength of the light.
On the other hand, as for the wave plate, there is a wave plate what is called Fresnel rhomb type utilizing the phase change associated with total reflection (for example, refer to Non Patent Literature 1). In the Fresnel rhomb type wave plate, light is incident on a surface of a prism, and after changing phase of the light by totally reflecting the light in the prism, the light is emitted out the prism.